Minimal Conditions of Motor Inductions of Approach-Avoidance States: The Case of Oral Movements

The minimal conditions to elicit affective responses via approach-avoidance movements were explored by using oral movements (total N = 1,363). To induce oral movements, words were construed whose consonants (and vowels) wandered either from front to back of the mouth (e.g., PEKA, inward, like swallowing, approach) or from back to front (e.g., KEPA, outward, like spitting, avoidance). Participants preferred inward over outward consonant wanderings when reading only 2 phonemes (e.g., PEKA vs. KEPA), single letters (e.g., PK vs. KP), and even when only listening to a speaker uttering such stimuli (Experiments 1-4). Vowel wanderings had no systematic effect. The larger the consonantal inward and outward jumps, irrespective from where they started in the mouth, the stronger was their affective impact (Experiments 6-7). Visual presentation of words generally evoked stronger in-out effects than listening to a speaker uttering the words, which speaks against a sound symbolism explanation. Informing theorizing also on the much more common manual approach-avoidance inductions, these findings show that approach-avoidance movements can elicit affect by activating only the starting and ending point of a spatial movement gradient, even involving differing muscles for these spots, respectively. Also, the present findings imply that the magnitude of the distance of the spatial approach-avoidance gradient matters (the larger the distance, the larger the affective response), and that such effects can be induced by mere observation (by only listening to a speaker).